"Don't tell me they don't use money in the 23rd century.
"Well, we don't."
You know, I've never taken this to mean anything more than that people in the future don't walk around with coins in their pockets or bills in their wallets. But DeSalle will bet you CREDITS to navy beans they still have ways of conducting financial transactions.
I'm in agreement. Remember, in the movie Kirk made a comment about "they're still using money; we have to get some" (paraphrased). Basically, the Federation operates on a sort of cashless society for most things - particularly in Starfleet - but that doesn't mean the idea of having to pay for what you get is obsolete.
It's like now, in some places - I was flabbergasted when I was looking for a pay phone at a local mall and the only one I found
did not accept coins. This pay phone only accepted cards. Since I don't carry a cell phone with me, I had to hunt up some shop clerk who would actually allow me to call a taxi so I could get home!
Obviously this is a situation that wouldn't work except on the most "civilized" (aka technologically advanced) planets like Earth or Vulcan. Remember when Ensign Ro and Picard were on their undercover assignment in the episode where she defected to the Maquis? She was posing as a prostitute and had to remind Picard that he needed to show his currency and they were supposed to be negotiating her price. I'm sure the underground economy is just as prevalent in the 24th century as it is in the here-and-now, and there are some kinds of transactions that people understandably don't want recorded in some Federation bank...
BTW, the scene with Kirk, Gillian, and the pizza? Kirk would have been justified in not offering to pick up the cheque anyway, for two reasons: One, he didn't have much 20th century currency and had to save it in case of a real emergency; two, it was
Gillian who issued the invitation. Of course, she hoped Kirk would be a gentleman, but alas...
